Chronic toxicity of an environmental contaminant mixture to young (or larval) striped bass

Abstract

Larvae of striped bass (Morone saxatilis (Walbaum)) were exposed to a mixture of organic and inorganic contaminants in fresh well water and 2 g L⁻¹ saline water for 30 days and in 5 g L⁻¹ saline water for 90 days.

Environmental concentrations (ECs) of organic and inorganic chemicals were estimated for the Chesapeake Bay area. Striped bass were exposed to the EC, 0.25 EC, 0.5 EC, 2 EC, 4 EC, and a solvent control to simulate potential conditions in their spawning and nursery habitats of the Chesapeake Bay. The sensitivities of striped bass as determined by survival depended on the characteristics of the exposure water. Larvae exposed in fresh well water were the most susceptible to the contaminant mixture; the 2 and 4 EC treatments caused significant (P:5 0.05) mortality within 30 days. In the 2 g L⁻¹ salinity water, the 4 EC treatment caused significant mortality after 30 days of exposure. Larvae exposed to the contaminant mixture for 90 days in the 5 g L⁻¹ saline water incurred significant mortality in the 2 and 4 EC treatments. We concluded that the age of the larvae, concentration of the contaminants, and salinity of the environment must be considered in evaluating the influence of environmental contaminants on the decline of striped bass along the east coast.